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The clustering behavior of three well clustered acrylate ionomers, i.e. poly(ethyl acrylate -co-Na acrylate) (PEA), poly(styrene-co-Na acrylate) (PS), and poly(vinylcyclohexane-co-Na acrylate) (PVCH) ionomers, was compared. It was found that the cluster phase became dominant at ca. 5mol% for the PEA and PS ionomers but at 9mol% for the PVCH ionomer. In addition, the temperature differences between...
Polarized Raman macrospectrometry and confocal Raman microspectrometry have been used to evaluate the uniaxial draw of polyethylene (PE) at a draw ratio of ∼6. The draw was conducted by solid-state extrusion. The PE samples tested were synthesized to different molecular weights by slurry and gas phase processes at different temperatures. Raman spectra offer an important evaluation of draw, with bands...
The molecular shape of well-defined poly(2-ethyl-2-oxazoline) (PEOz) chains in tetrahydrofuran (THF) at room temperature has been studied by a combination of static and dynamic light scattering and viscometry in the framework of the hard-sphere model. Data of the z-average radius of gyration as well as equivalent sphere radii such as the hydrodynamic radius (R H ), the viscometric radius (R...
Fluorinated polyurethanes (FPUs) were synthesised from 4,4′-methylenebis(phenylisocyanate) (MDI), 1,4-butandiol (BDO), as a chain-extender, and soft perfluoropolyetheric block (ZDOLTX), by a two-step polymerisation technique, following specific procedures to obtain chains with a regular-segmented structure or polymers characterised by having high hard (MDI–BDO) segment polydispersity. Calorimetric...
The fatigue behavior of short glass-fiber reinforced nylon 66 under stress controlled fatigue tests was studied on the basis of the nonlinear dynamic viscoelasticity measurements. In order to analyze the effect of nonlinear viscoelasticity on the fatigue behavior, quantitative measurements of nonlinear viscoelasticity have been carried out based on Fourier analysis. It was found that the nonlinear...
We report a remarkable feature of the cocoon silk spun by Araneus diadematus spiders, as revealed by electron diffraction: transverse sections of the fibres exhibit significant microstructural anisotropy. Although the mechanical processes of fibre spinning and drawing are uniaxial, the spider is able to achieve multiaxial control of molecular order. In contrast, complex flow patterns are used to obtain...
The present work focuses on the effects of thermomechanical history on the structure and mechanical behaviour of PVDF. In the first part of our investigation differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) are used to follow the evolution of the structure of PVDF after different annealing treatments or deformation. Processing has a significant impact on the quantities...
Hybrid organic/inorganic nanocomposites are being developed to improve the physical and mechanical properties of polymeric materials without adversely effecting their processing characteristics. One such nanocomposite developed by Toyota and commercialized by Ube Industries is the nylon-6/montmorillonite clay nanocomposite. The mechanism of reinforcement in nylon-6/clay nanocomposite materials is...
Nanoindentation technique and scanning force microscopy have been used to measure directly the polyethylene modulus along the chain axis. Single crystals of polyethylene were employed in order to obtain well-aligned chain segments. To minimize effects of scanner creep, a Z scan rate of 3Hz was employed. The “X Rotate” value of 25° was selected to eliminate effects of lateral tip motion. The results...
Transmission electron microscopy (TEM) and electron diffraction (ED) are used to study the morphology of a semicrystalline polyolefin diblock copolymer polyethylene-b-atactic-polypropylene (PE-b-aPP) and its blend with polyethylene homopolymer. By using RuCl 3 /NaClO as the staining agent, both the contrast between amorphous PP and amorphous PE regions and the contrast between amorphous PE...
The effects of moisture and strain rate on the tensile properties of poly(hydroxy ester ether) (PHEE) were investigated. Water was shown to act as a plasticiser which lowered the room temperature tensile strength and modulus. The strain at failure increased with increasing water content and a change in the mode of failure was observed. Brittle failure occurred when the moisture content was low. As...
The shear-induced morphologies produced by channel die processing of a semicrystalline ethylene/ethylene–propylene/ethylene (E/EP/E) block copolymer were investigated as a function of processing conditions. The microphase separation of the block constituents under the processing conditions used in this work leads to a lamellar stack morphology, referred to as the B population, whose dimensions are...
Structure parameters of various poly(p-phenylene terephthalamide fibers have been investigated using WAXD and correlated with mechanical properties. The mechanical properties examined were modulus E and strength σ; the pertinent structural parameters include orientation angle φ 200 , lattice constants a, b, c, paracrystalline parameter g II, apparent crystal sizes ACS 110 ,...
This work describes the synthesis and macromolecular reactions of maleic anhydride (MA)–methyl methacrylate (MMA) binary and MA–trans-stilbene (Stb)–n-butyl methacrylate (BMA) ternary reactive copolymers with γ-aminopropyltriethoxysilane (APTS) as a polyfunctional crosslinker. Copolymers with given compositions of MA–MMA (77.7mol%) and MA (22.7mol%)–Stb–BMA (54.2mol%) are synthesised by radical binary...
The crystalline structure of poly(hexamethylene sebacate) has been studied using transmission electron microscopy and X-ray diffraction. Molecular chains adopt a slightly distorted all-trans conformation and pack in a Monoclinic unit cell with space group P12 1 /n1. The unit cell contains two chain segments, with a chain setting angle similar to that reported for polyethylene. Similar results...
Poly (ethylene oxide) (PEO) and poly (trimethopropane trimethacrylate) (PTMPTMA) interpenetrate networks have been synthesized. The confined crystallization behavior of PEO in the PTMPTMA networks has been investigated by a differential scanning calorimeter and scanning electron microscope. The degree of PEO crystallinity in PEO/PTMPTMA interpenetrate networks reduces with the increase of PTMPTMA...
A systematic study of physical aging in polymers that have been plasticized by the addition of dyes and polymeric plasticizers is undertaken using the heat capacity as the structural probe. The dyes are actually dye sets and are mixtures of various dyes with slight structural differences, each with a different glass transition temperature (T g ). The polymeric plasticizers are low molecular...
The evolution of the mechanical properties and structure of poly(p-phenylene terephthalamide) (PPTA) fibers with different post-treatment methods involving heat, tension, hydrostatic pressure, and different environments was systematically investigated. Wide-angle X-ray diffraction measurements reveal that the crystal structure of PPTA fiber is not stable and changes upon post-treatment. The cooperative...
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